To be honest I never had Issues with Battery Life on my ThinkPad. I've gotten out 10-12 hours with the 96Wh Battery and never felt the need for much more.
I think most people who are so wowed by Macs bought just a garbage Windows Machine (e.g. almost everything from Asus and Acer) before and then splurged the money for a nice one, so obviously it's so much better in comparison.
Is that under Windows or Linux? It’s not awful, but depending on usage a MacBook can do 16h+ with the same size battery, especially if put into low power mode, which is substantially better.
The smaller 13” Air also gets similar numbers despite its smaller battery, which is a big deal for people who don’t want to lug around a 15/16” laptop.